[media] e4000: fix crash when attach fails

Callbacks were set even attach failed. This leads calling
.release() in error case and resulted crash.
Reported-by: NOliver Schinagl <oliver@schinagl.nl>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/tuners/e4000.c

@@ -366,9 +366,6 @@ struct dvb_frontend *e4000_attach(struct dvb_frontend *fe,
 
 	priv->cfg = cfg;
 	priv->i2c = i2c;
-	fe->tuner_priv = priv;
-	memcpy(&fe->ops.tuner_ops, &e4000_tuner_ops,
-			sizeof(struct dvb_tuner_ops));
 
 	/* check if the tuner is there */
 	ret = e4000_rd_reg(priv, 0x02, &chip_id);
@@ -389,6 +386,10 @@ struct dvb_frontend *e4000_attach(struct dvb_frontend *fe,
 			"%s: Elonics E4000 successfully identified\n",
 			KBUILD_MODNAME);
 
+	fe->tuner_priv = priv;
+	memcpy(&fe->ops.tuner_ops, &e4000_tuner_ops,
+			sizeof(struct dvb_tuner_ops));
+
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0);